1. Field of the Invention
The invention relates to a circuit and a method for the creation and the operation of the plasmas of high pressure short-arc lamps having small dimensions.
2. Description of the Related Art
High pressure cold cathode gas discharge lamps, as, for example, are used in vehicle headlights, require special circuits for controlling the ignition and the resulting stable operation of the arc. The operation using alternating current causes the arc to radiate a white light that is uniformly distributed. In addition, the operation of gas discharge lamps using alternating current is desirable in order to achieve a high durability.
When operating using alternating current a critical phase of the operation is reached at the change in polarity, the so called “zero crossing point”, in which the lamp can extinguish itself when the sum, made up of the voltage drop across the arc length and across both electrode plasma transition zones, is greater than the external lamp operating voltage of the pre-switching device.